Apparatus for detecting splices and breaks in filaments and fibers



y 0, 1968 E. P. CARTER ETAL 3,395,258

APPARATUS FOR DETECTING SPLICES AND BREAKS IN FILAMENTS AND FIBERS Filed Aug. 5, 1966 so A 46 Ill 36 32 i 54 5 6 1 58 6 INVENTORS ERNEST I? CARTER F I G, 2, ROBERT e BELL, JR.

ALTON P. CARROLL, R.

MW M

ATTORN United States Patent 3,395,258 APPARATUS FOR DETECTING SPLICES AND BREAKS IN FILAMENTS AND FIBERS Ernest P. Carter, Robert P. Bell, Jr., and Alton P. Carroll,

Jr., Decatur, Ala., assignors to Monsanto Company,

St. Louis, Mo., a corporation of Delaware Filed Aug. 3, 1966, Ser. No. 570,084 8 Claims. (Cl. 20061.18)

This invention relates to apparatus for detecting splices and breaks in filaments and fibers, and more particularly relates to improved apparatus for detecting such splices and breaks in an improved manner.

In the evolving technology of fiber utilization, high performance materials such as boron are finding increasing areas of application. For example, it has been found that when a number of boron filaments are collected into bundles and braided with a strong, flexible material such as nylon, such a composite filament can be processed utilizing textile techniques including weaving.

Difiiculties have, however, been encountered in processing filaments of such materials due to their brittleness and propensity to breaking during processing. In addition to the problem of reducing productivity, breakage of such filaments results in splices which are, because of quality considerations, undesirable in the finished product.

Obviously, during filament processing such as the braiding operation described above, it is desirable to detect both the presence of breaks and splices in the filaments. Current detection systems capable of performing this function are unsatisfactory, however, because they utilize mechanical tripping systems which necessarily require the application of a relatively great amount of force against the filament being processed. This application of force is entirely unsatisfactory where highly brittle fibers, such as those of boron, are encountered.

According to the instant invention it has been found that the above difiiculties can be overcome by utilizing an electrically conductive wire or member having a U-shaped portion with a pivotal mounting at its bottom. Extending from one arm of the U-shaped portion is a segment terminating in a hook-shaped section which will contact the filament. Because the wire has a low mass, the contact pressure is very light. Extending between the arms of the U-shaped section is an electrically conductive member which, with the wire, forms a closed electrical circuit when either arm touches it. Disposed on the upstream side of the hook-shaped section, is an enlarged plate having an aperture closely but slidably fitted around the filament.

In operation, if a break occurs in the filament the electrically conductive wire will pivot so that one arm of the U-shaped portion contacts the electrically conductive member. Should a splice occur the enlarged plate is, because of the restrictive size of the aperture, carried along the filament until it contacts the hook-shaped portion, again causing the wire to pivot so that one of the arms of the U-shaped portion contacts the electrically conductive plate. In either case contact between the wire and plate or member results in the closing of the electrical circuit which will either indicate to the operator through a signal that something is amiss or will shut down the apparatus to which it is attached.

Accordingly, it is an object of this invention to provide apparatus for detecting both splices and breaks in a continuous filament.

Another object of this invention is to provide filament splice and break detecting apparatus which is simple to operate and economical to install.

Yet another object of this invention is to provide apparatus for detecting breaks and splices in a rather fragile filament in a manner such that only a very slight contact with the filament is required.

A still further object of this invention is to provide filament splice and break detecting apparatus which is substantially electrical in nature and therefore capable of quick response to these undesirable conditions.

Further objects of this invention are the provision of splice and break detecting apparatus which is simple to operate, economical, quickly responsive, and of itself is not detrimental to the filament.

These and other objects and advantages of this invention will be more apparent to references to the following specification, appended claims, and drawing wherein:

FIGURE 1 is a side elevation of the splice and break detecting apparatus installed on a braiding machine;

FIGURE 2 is an enlarged fragmentary, detailed view of the operative elements of the splice and break detecting apparatus according to the invention; and

FIGURE 3 is a detailed, enlarged view of the splice detecting plate utilized in the novel break-splice detecting apparatus according to this invention.

In order to better understand the construction and use of this novel splice and break detecting apparatus, it will be described in relationship to its use in filament braiding apparatus. It is to be understood, however, that various other uses may be found for this novel device. It can be utilized, for example, wherever it is necessary or desirable to detect breaks or splices in a continuous filament such as in the drawing of wire and the manufacture or processing of all kinds of textile fibers. Other uses will be readily apparent to those skilled in the art.

With continued reference to the accompanying figures wherein like numerals designate similar parts throughout the various views, and with initial attention directed to FIGURE 1, reference numeral 10 designates generally a braiding machine with which the splice and break detecting apparatus, designated by reference numeral 12, is combined. A plurality of feed reels 14 supply filaments 16 to the break and splice detecting apparatus 12 from which they pass to an apertured plate 18 where they are combined into a single strand 20. This strand passes through the braiding apparatus 10 and is rewound on a driven take-up reel 22.

The braiding apparatus itself consists generally of a plurality of bobbin carriers 24 including guides 26 through which braiding thread or yarn 28 fed from bobbins 30 is threaded. The carriers 24 are in track forming grooves in plate 32 which direct them and their associated bobbins 30 in a predetermined pattern around the strand 20 as it passes through an aperture in the center of the plate 32. Motion is imparted to the carriers 24 by a train of gears (not shown) located beneath plate 32 and arranged in a known manner.

Yarns 28 are directed from the guides 26 into a former plate 34 which brings them into close contact with the strand 20. Suitable driving force is provided by drive means 36 which may be either a self-contained motor unit or a gear box for receiving power from a drive shaft, common to several of these machines. Each take-up reel 22 is equipped with a spur gear 38 which is driven through a worm 40 and spur gear 42 drive which receives motive power from the drive means 36 to the gears (not shown) beneath plate 32. The operation of braiding machinery is well known and it is not necessary to discuss it in detail.

The output of drive means 36 is controlled by a clutch (not shown) which is operable either through actuation of handle 48 or electrically through a solenoid arrangement contained in the control box 50. The use of clutches both manually and electrically actuated is well known and further discussion of this subject is believed to be unnecessary.

Referring now to FIGURES 2 and 3 the structure and mode of operation of the splice and break detection apparatus according to the instant invention is clearly shown.

Continuous filaments 16 extend through a guide plate 52 constructed of electrically conductive material. The filaments 16 are maintained in spaced relationship from one another and the guide plate 52 by insulating grommets 54. Plate 52 is mounted on a hollow pedestal 56 around which an electrically conductive wire 58 extends connecting plate 52 to the clutch actuating solenoid in control box 50. Thus, plate 52 and wire 58 form, with the actuating solenoid, a part of an electrical circuit.

A rod 60 is spacedly mounted around the periphery of plate 52 and is electrically insulated therefrom. Secured to the rod is an electrically conductive wire 62 extending into the control box 50 and connected to the clutch actuating solenoid to form an electrical circuit extending from rod 60 through the solenoid and wire 58 to plate 52. The rod 60 is electrically connected to and forms a pivot point for electrically conductive members or wires 64, one of which is mounted next to each of the insulating grommets 54.

Each of the members 64 consists of a U-shaped portion 66 having a pair of outwardly extending arms between which the plate 52 is received. Since the pivot point 60 is mounted at the bottom of the U-shaped portion, the arc of travel of either of the arms of the U-shaped portion 66 passes through and is intercepted by the electrically conductive plate 52. Another segment 68 of the wire or member 64 extends upwardly from one of the arms of the U-shaped portion 66 and terminates in a hook-shaped section 70. The hook-shaped section 70 is designed to partly encircle and lightly rest on the filament 16.

The portion of the invention directed to the detection of splices in the filaments 16 is shown clearly in FIG- URES 2 and 3. This portion of the apparatus consists of an enlarged member or plate 72 having an aperture 74 therein. This plate 72 normally rests on one of the insulating grommets 54 with the filament 16 passing through the aperture 74. The dimensions of plates 72 are such that aperture 74 closely yet slidably fits around the filament 16 with the exterior dimensions selected to be too large to pass through hook-shaped section 70.

The conductive wire 64 and plate 72 are shown in FIG- URE 2 in their normally operative positions with the filament 16 passing through aperture 74 and hook-shaped portion 70 with both arms of the U-shaped section spaced from the electrically conductive plate 52. If the filament 16 should break, the wire 64 will, because of its weight distribution and the location of the pivot point 60, fall downwardly with the upper arm of the U-shaped portion 66 contacting the electrically conductive plate 52. This completes the circuit from plate 52 through wire 58 to the clutch actuating solenoid in control box 50, through wire 62 to ring 60 and back to electrically conductive plate 54 through the wire 64. Thus, the solenoid is actuated and the clutch is disengaged from the drive system 36 whereupon the braiding apparatus ceases operation. The apparatus remains inoperative until the break is corrected and the clutch reengaged by manually actuating handle 48.

If a splice or other enlargement is encountered on the filament 16, it will not pass through aperture 74 in plate 72 which will thereby be carried with the filament into engagement with hook-shaped section 70. Plate 72 will force the wire 64 to pivot upwardly so that the lower arm of the U-shaped portion 66 contacts electrically conductive plate 52. This, again, completes the circuit from electrically conductive plate 52 through wire 58 to the clutch actuating solenoid, through wire 62 to ring 60 and back to plate 52 through the lower arm of the U- shaped portion 66. This deactivates the machine until the deficiency in filament 16 is corrected and the clutch reengaged.

The specific interrelationship between the various parts of the splice and break detecting apparatus shown in FIG- URE 3 can be varied to produce the same results. For example, the conductive plate 52 need not be a part of the circuit, but substitution of an electrically conductive wire between the arms of the U-shaped portion may be successfully utilized. Furthermore, the wire 64 could be a straight length spacedly sandwiched between two electrically conductive plates and pivoted intermediate of its ends so that any rotation thereof could complete the circuit.

The shape of the plate 72 is not critical, the only restriction being that it is large enough not to pass through hook-shaped section 70. Furthermore, the aperture '74 must be of a size to pass a dimensionally correct filament 16 but not pass a defect such as a splice. An alternative to the automatic clutch actuation system would be the utilization of an indicating light, horn, or other means responsive to the condition of the electrical circuit formed by plate 52, wire 58, wire 62, ring 60, and wire 64. Automatic actuation is, however, preferred. Where the size of filament utilized is always the same the splice detection system can consist of an aperture in hook-shaped section closely but slidably fitted about filament 16. Then a splice will pivot wire 64 directly. The plate 72 system is preferred, however, since a change in filament size will necessitate only a change in plates rather than a change in wires 64.

It will be apparent that by utilizing the teachings of this invention a splice and break detecting apparatus which is simple, economical, and easily utilized in confined spaces may be constructed. The system of the instant invention requires only very slight pressure against the filament 16 since the mass of wire 64 is very low. This is directly contrastable to the great amount of pressure required in the mechanically actuated systems presently in vogue. While light pressure on the filament is desirable in all cases it is especially desirable where the newer high performance filaments which are extremely brittle are involved.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

We claim:

1. Apparatus for detecting defects in elongated filaments comprising:

(a) an electrically conductive, pivotally mounted element;

(b) means on said element adapted to contact said filament;

(c) electrically conductive means located in the pivotal arc of said element;

(d) an electrical circuit having said element and said conductive means as components whereby as said means on said member ceases to contact said filament said element will pivot into contact with said electrically conductive means closing said circuit;

(e) an enlarged member, means mounting said member for movement relative to said electrically conductive means, said member having an aperture therein adapted to closely, slidably fit about said filament whereby an enlargement on said filament will move said member into contact with said means on said wire causing it to pivot into contact with said electrically conductive means closing said circuit.

2. Apparatus according to claim 1 wherein said pivotally mounted element includes a substantially U-shaped portion with the pivot point at the bottom of said portion.

3. Apparatus according to claim 2 wherein said electrically conductive means extends between the outwardly extending arms of said U-shaped portion.

4. Apparatus according to claim 3 wherein said means on said pivotally mounted element adapted to contact said filament includes a segment of said element extending outwardly from an arm of said U-shaped portion and terminating in a hook-shaped section adapted to partially encircle and contact said filament whereby a break in said filament causes said U-shaped portion to pivot into contact with said conductive means and close said electrical circuit.

5. Apparatus according to claim 4 wherein said enlarged member is normally adapted to be disposed on said filament at a point upstream from said hook-shaped section on said segment of said element whereby an enlargement on said filament will force said pivotally mounted element in contact with said electrically conductive means to thereby close said electrical circuit.

6. Apparatus according to claim 5 wherein said electrically conductive means is also a guide plate provided with insulating grommets through which said filaments pass.

7. Apparatus for detecting defaults in an elongated filament comprising:

(a) an electrically conductive wire having a U-shaped portion and a segment extending outwardly from an arm of said U-shaped portion terminating in a hook-shaped section adapted to partially encircle and contact said filaments;

(b) a pivotal mounting in the bottom of said U-shaped portion whereby the arms of said portion are swingable through predetermined arcs;

(c) electrically conducted means extending between said arms of said U-shaped portion and intercepting said predetermined arcs;

(d) a normally open electrical circuit including said wire and said electrically conductive means as components thereof whereby contact between said electrically conductive means and either of said arms of said U-shaped portion closes said circuit;

(e) an enlarged member having an aperture therein adapted to closely, slidably fit about said filament, said member being sized such that it will not pass through said wire hook-shaped section;

(f) said enlarged member normally adapted to be disposed on said filament at a point upstream from said hook-shaped section of said wire whereby an enlargement on said filament will force said wire into contact with said section;

(g) said wire being formed with its weight distributed about said pivotal mounting such that an interruption in said filament will cause one of said arms to pivot into contact with said electrically conducted means and will permit said enlarged member to pivot another one of said arms into contact with said electrically conducted means when it is forced against said hook-shaped section by a filament enlargement; and

(h) means responsive to the condition of said circuit.

8. Apparatus according to claim 7 wherein said means responsive to the condition of said circuit is a clutch actuating solenoid.

References Cited UNITED STATES PATENTS 1,423,398 7/1922 Connell et al 20061.13 2,242,875 5/ 1941 Wachsman ZOO-61.14 2,329,427 2/ 1943 Vossen ZOO-61.14

BERNARD A. GILHEANY, Primary Examiner.

F. E. BELL, Assistant Examiner. 

1. APPARATUS FOR DETECTING DEFECTS IN ELONGATED FILAMENTS COMPRISING: (A) AN ELECTRICALLY CONDUCTIVE, PIVOTALLY MOUNTED ELEMENT; (B) MEANS ON SAID ELEMENT ADAPTED TO CONTACT SAID FILAMENT; (C) ELECTRICALLY CONDUCTIVE MEANS LOCATED IN THE PIVOTAL ARC OF SAID ELEMENT; (D) AN ELECTRICAL CIRCUIT HAVING SAID ELEMENT AND SAID CONDUCTIVE MEANS AS COMPONENTS WHEREBY AS SAID MEANS ON SAID MEMBER CEASES TO CONTACT SAID FILAMENT SAID ELEMENT WILL PIVOT INTO CONTACT WITH SAID ELECTRICALLY CONDUCTIVE MEANS CLOSING SAID CIRCUIT; 